Powertrain, generic (extended)

P23EB Camshaft A Position Signal Output Circuit High (Bank 2)

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P23EB is the opposite fault to P23EA: the bank 2 camshaft A output line, which the ECM drives as a switched low-side signal for another module, stays high when it should be pulled low. Typical reasons are a wire touching a supply circuit, moisture in a connector or a defective driver in the ECM. GM checks the bank 1 version P2616 while the output is commanded low and declares a short to power at 0.5 ohm or less, with system voltage at least 11 V and 40 of 50 samples failing (Type C, no MIL). Nothing comparable is published for P23EB itself, so these figures only serve as a guide. Unlike sensor codes such as P0345, the engine's own timing is not affected; the risk lies with the module downstream, which loses its phase reference.

Likely causes

Output wire shorted to a battery or 5 V supply wire in the harness
Water ingress bridging terminals
ECM output transistor no longer switching to ground

Symptoms

  • Code present without drivability complaint
  • Related fault codes in the receiving control module
  • Comfort functions such as start-stop deactivated

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

engine control modulecam position signal a b2 outputwiring harness

Related codes

P23E9P23EAP23EEP23F1P2616

References: gsi.ext.gm.com, law.cornell.edu.